The cochlear implant is the first neural prosthesis to achieve the technical success necessary for widespread clinical application. It provides the only effective therapy for restoring sound sensation and speech understanding to the profoundly deaf. Over the past 20 years dramatic improvements in patients' performance with these devices have been achieved. Currently the average speech understanding score for implanted adults is between 80-100% correct. These advances have derived substantially from the collective efforts of researchers in a broad array of scientific disciplines. This close collaboration and cooperation has been fostered in large part through a series of biennial research conferences, originating with the 1983 Gordon Research Conference on Implantable Auditory Prostheses. These conferences are the only forum in which implant research issues are the sole focus. Topics to receive emphasis in this meeting are the coding of pitch and music, and the effects of CMS plasticity and learning. Complex pitch and music have proven to be particularly difficult to convey in a cochlear implant. Recent studies have started to elicidate the underlying neuroscience of complex pitch. Learning and plasticity have long been complex issues surrounding hearing aids and implants. A special session will explore the time course and neurological data of plasticity and learning as it applies to cochlear implants. In addition to these topics we will examine the latest research on (1) binaural processing, (2) combined acoustic (low frequency) and electric (high frequency) hearing, (3) channel interaction, (4) signal processing and speech in noise, (5) coding of pitch and music perception, (6) perceptual organization of speech, (7) electrode technology and design, (8) cochlear implants in children, (9) CNS plasticity and cognitive factors, and (10) future prostheses. In summary, the conference will continue the tradition of combining information from a wide range of disciplines in an effort to better understand electrical stimulation of the cochlea and to improve the performance of patients fitted with cochlear implants. This application seeks partial support for this conference, scheduled at the Asilomar Conference Center, Pacific Grove, CA July 30 to August 4, 2005.